1. Field of the Invention
The present invention relates generally to tissue treatment systems and in particular to methods, systems and compositions for making and using a pourable and/or injectable gel or gel-forming solution.
2. Description of Related Art
Clinical studies and practice have shown that providing a reduced pressure in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but application of reduced pressure has been particularly successful in treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, including migration of epithelial tissue and subcutaneous tissue from the healthy tissue towards the tissue site, faster healing and increased formation of granulation tissue. Typically, reduced pressure is applied to tissue through a porous pad or other manifolding device. The porous pad contains cells or pores that are capable of distributing reduced pressure to the tissue and channeling fluids that are drawn from the tissue. The porous pad often is incorporated into a dressing having other components that facilitate treatment.
Typically, the porous pad or other manifolding device is sized to fit the existing wound and placed in contact with the wound. The pad or device is then periodically replaced with smaller pieces of dressing as the wound begins to heal and becomes smaller. While use of reduced pressure therapy with the porous pad or other manifolding device has been highly successful, there still exist various difficulties with this process. For example, it may be difficult to obtain a porous pad or other manifolding device of a proper width, length or depth to adequately fill the wound. Further, as the porous pad or other manifolding device is removed it may also remove healthy tissue, thereby causing further trauma to the tissue site.
It has been previously proposed to use biodegradable materials to make the porous pad or other manifolding device, therefore negating the need to remove it from the tissue site. Further, other have attempted various methods to manufacturing biodegradable polymers in different shapes. In all of these methods, however, the biodegradable polymer is formed in advance into a particular shape. Individual wounds, however, are of inconsistent shapes and sizes.
Cavi-Care™ is a foam dressing produced by Smith & Nephew Healthcare Limited that is a two-part room temperature vulcanizing foam, where a polydiethylsiloxane base is mixed with a platinum catalyst and hydrogen gas-releasing agents, which react together to form that is poured onto a wound, where it conforms to the shape of the wound. Cavi-Care™ is not biodegradable and must be removed and cleansed on a regular basis. The foam Cavi-Care™ dressing is not porous enough to be used with reduced pressure therapy.
A need exists, therefore, for a bioabsorbable composition that conforms to the exact shape of a wound, where the composition may serve as a dressing. The present invention addresses that need.